/* * Copyright 2019 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "fields/packet_field.h" #include "util.h" PacketField::PacketField(std::string name, ParseLocation loc) : loc_(loc), name_(name) {} std::string PacketField::GetDebugName() const { return "Field{Type:" + GetFieldType() + ", Name:" + GetName() + "}"; } ParseLocation PacketField::GetLocation() const { return loc_; } std::string PacketField::GetName() const { return name_; } Size PacketField::GetBuilderSize() const { return GetSize(); } Size PacketField::GetStructSize() const { return GetSize(); } int PacketField::GenBounds(std::ostream& s, Size start_offset, Size end_offset, Size size) const { // In order to find field_begin and field_end, we must have two of the three Sizes. if ((start_offset.empty() && size.empty()) || (start_offset.empty() && end_offset.empty()) || (end_offset.empty() && size.empty())) { ERROR(this) << "GenBounds called without enough information. " << start_offset << end_offset << size; } if (start_offset.bits() % 8 != 0 || end_offset.bits() % 8 != 0) { ERROR(this) << "Can not find the bounds of a field at a non byte-aligned offset." << start_offset << end_offset; } if (!start_offset.empty()) { s << "size_t field_begin = (" << start_offset << ") / 8;"; } else { s << "size_t field_begin = end_index - (" << end_offset << " + " << size << ") / 8;"; } if (!end_offset.empty()) { s << "size_t field_end = end_index - (" << end_offset << ") / 8;"; // If the field has a known size, use the minimum for the end if (!size.empty()) { s << "size_t field_sized_end = field_begin + (" << size << ") / 8;"; s << "if (field_sized_end < field_end) { field_end = field_sized_end; }"; } } else { s << "size_t field_end = field_begin + (" << size << ") / 8;"; s << "if (field_end > end_index) { field_end = end_index; }"; } s << "auto " << name_ << "_it = to_bound.Subrange(field_begin, field_end - field_begin); "; return 0; // num_leading_bits } bool PacketField::GenBuilderParameter(std::ostream& s) const { auto param_type = GetBuilderParameterType(); if (param_type.empty()) { return false; } s << param_type << " " << GetName(); return true; } bool PacketField::BuilderParameterMustBeMoved() const { return false; } bool PacketField::GenBuilderMember(std::ostream& s) const { return GenBuilderParameter(s); } void PacketField::GenBuilderParameterFromView(std::ostream& s) const { s << "view.Get" << util::UnderscoreToCamelCase(GetName()) << "()"; } bool PacketField::IsContainerField() const { return false; } const PacketField* PacketField::GetElementField() const { return nullptr; } void PacketField::GenStringRepresentation(std::ostream& s, std::string accessor) const { s << "\"REPRESENTATION_UNIMPLEMENTED " << GetFieldType() << " " << accessor << "\""; } int PacketField::GetRustBitOffset( std::ostream&, Size start_offset, Size end_offset, Size size) const { // In order to find field_begin and field_end, we must have two of the three Sizes. if ((start_offset.empty() && size.empty()) || (start_offset.empty() && end_offset.empty()) || (end_offset.empty() && size.empty())) { ERROR(this) << "GenBounds called without enough information. " << start_offset << end_offset << size; } if (start_offset.bits() % 8 != 0 || end_offset.bits() % 8 != 0) { ERROR(this) << "Can not find the bounds of a field at a non byte-aligned offset." << start_offset << end_offset; } return 0; // num_leading_bits } bool PacketField::GenRustNameAndType(std::ostream& s) const { auto param_type = GetRustDataType(); if (param_type.empty()) { return false; } s << GetName() << ": " << param_type; return true; } void PacketField::GenBoundsCheck(std::ostream& s, Size start_offset, Size, std::string context) const { Size size = GetSize(); if (size.bits() < 8) { return; } s << "if bytes.len() < " << start_offset.bytes() + size.bytes() << " {"; s << " return Err(Error::InvalidLengthError{"; s << " obj: \"" << context << "\".to_string(),"; s << " field: \"" << GetName() << "\".to_string(),"; s << " wanted: " << start_offset.bytes() + size.bytes() << ","; s << " got: bytes.len()});"; s << "}"; }